#120 - localized package "main" and "ui/cells"

src/de/deadlocker8/budgetmaster/logic/utils/Strings.java

src/de/deadlocker8/budgetmaster/main/Main.java

src/de/deadlocker8/budgetmaster/main/_de.properties

...deadlocker8/budgetmaster/ui/cells/CategoryBudgetCell.java

src/de/deadlocker8/budgetmaster/ui/cells/CategoryCell.java

src/de/deadlocker8/budgetmaster/ui/cells/PaymentCell.java

...de/deadlocker8/budgetmaster/ui/controller/Controller.java

...r8/budgetmaster/ui/controller/SplashScreenController.java